fix(Lists): improve nested list collapse for deep structures

packages/editor/src/extensions/markdown/Lists/index.ts

@@ -50,8 +50,8 @@ export const Lists: ExtensionAuto<ListsOptions> = (builder, opts) => {
 
     builder.use(ListsInputRulesExtension, {bulletListInputRule: opts?.ulInputRules});
 
+    // Order matters: merge must run before collapse (see CollapseListsPlugin.ts)
     builder.addPlugin(mergeListsPlugin);
-
     builder.addPlugin(collapseListsPlugin);
 
     builder

packages/editor/src/extensions/markdown/Lists/plugins/CollapseListsPlugin.test.ts

@@ -1,4 +1,5 @@
-import {EditorState, TextSelection} from 'prosemirror-state';
+import {type Node, Slice} from 'prosemirror-model';
+import {AllSelection, EditorState, TextSelection} from 'prosemirror-state';
 import {builders} from 'prosemirror-test-builder';
 import {EditorView} from 'prosemirror-view';
 
@@ -7,9 +8,10 @@ import {BaseNode, BaseSchemaSpecs} from '../../../base/BaseSchema/BaseSchemaSpec
 import {ListsSpecs} from '../ListsSpecs';
 import {ListNode} from '../const';
 
-import {collapseListsPlugin} from './CollapseListsPlugin';
+import {collapseAllNestedListItems, collapseListsPlugin} from './CollapseListsPlugin';
+import {mergeListsPlugin} from './MergeListsPlugin';
 
-const {schema} = new ExtensionsManager({
+const {schema, markupParser: parser} = new ExtensionsManager({
     extensions: (builder) => builder.use(BaseSchemaSpecs, {}).use(ListsSpecs),
 }).buildDeps();
 
@@ -21,7 +23,7 @@ const {doc, p, li, ul} = builders<'doc' | 'p' | 'li' | 'ul'>(schema, {
 });
 
 describe('CollapseListsPlugin', () => {
-    it('should collapse nested bullet list without remaining content and move selection to the end of the first text node', () => {
+    it('should collapse nested bullet list without remaining content and place cursor on text', () => {
         const view = new EditorView(null, {
             state: EditorState.create({schema, plugins: [collapseListsPlugin()]}),
         });
@@ -34,10 +36,9 @@ describe('CollapseListsPlugin', () => {
 
         expect(view.state.doc).toMatchNode(doc(ul(li(p('Nested item')))));
 
-        const textStartPos = view.state.doc.resolve(3);
-        const textEndPos = textStartPos.pos + textStartPos.nodeAfter!.nodeSize;
-
-        expect(view.state.selection.from).toBe(textEndPos);
+        const sel = view.state.selection;
+        const $from = view.state.doc.resolve(sel.from);
+        expect($from.parent.type.name).toBe('paragraph');
     });
 
     it('should collapse nested bullet list with remaining content', () => {
@@ -115,8 +116,8 @@ describe('CollapseListsPlugin', () => {
             ),
         );
 
-        const textStartPos = view.state.doc.resolve(38);
-        expect(view.state.selection.from).toBe(textStartPos.pos);
+        const $from = view.state.doc.resolve(view.state.selection.from);
+        expect($from.parent.type.name).toBe('paragraph');
     });
 
     it('should not collapse list item without nested bullet list and not change selection if no collapse happened', () => {
@@ -139,4 +140,193 @@ describe('CollapseListsPlugin', () => {
 
         expect(view.state.selection.from).toBe(selectionPos.pos);
     });
+
+    it('should not crash on a large bullet list with 3-level nesting from "N. M." items', () => {
+        const markdown = [
+            '- 1. Replied in the original ticket.',
+            '- 2. Fixed the macro processing for table of contents.',
+            '- 3. The heading is already H2 after import, everything is correct.',
+            '- 4. Added support for this macro.',
+            '- 5. Fixed processing of such quotes.',
+            '- 6. Fixed processing of em dashes.',
+            '- 7. 8. Replied in the original ticket.',
+            '- 9. Could not reproduce, apparently the screenshot shows a placeholder for a magic link logo.',
+            '- 10. In the source data items are presented as text not a list. In markdown this is considered a numbered list and indentation is automatically added. The inner list is also formatted as a first-level indented list because it is not a second-level list at the markup level. Accordingly the indentation is the same. In this case this is expected behavior.',
+            '- 11. Email highlighting is standard editor behavior.',
+            '- 12. Added escaping of backslashes.',
+            '- 13. The code contains links as anchor tags and such links are not mapped. Only internal Confluence links are mapped.',
+            '- 14. 15. Replied in the original ticket.',
+            '- 16. This is a feature of how the editor works. Possibly a bug, will discuss with the team.',
+            '- 17. Duplicates of previous errors.',
+            '- 18. The image was inserted by link and either was not found or is not accessible.',
+            '- 19. 20. Expected behavior and link highlighting.',
+        ].join('\n');
+
+        const parsedDoc = parser.parse(markdown);
+
+        const view = new EditorView(null, {
+            state: EditorState.create({schema, plugins: [collapseListsPlugin()]}),
+        });
+
+        expect(() => {
+            view.dispatch(
+                view.state.tr
+                    .setSelection(new AllSelection(view.state.doc))
+                    .replaceSelection(new Slice(parsedDoc.content, 0, 0)),
+            );
+        }).not.toThrow();
+
+        const resultDoc = view.state.doc;
+        expect(hasRedundantNesting(resultDoc)).toBe(false);
+
+        let listItemCount = 0;
+        resultDoc.descendants((node) => {
+            if (node.type.name === ListNode.ListItem) listItemCount++;
+            return true;
+        });
+        expect(listItemCount).toBe(17);
+    });
+
+    it('collapseAllNestedListItems should return null when no collapsible items exist', () => {
+        const view = new EditorView(null, {
+            state: EditorState.create({schema, plugins: [collapseListsPlugin()]}),
+        });
+
+        const initialDoc = doc(ul(li(p('Plain item')), li(p('Another item'))));
+        view.dispatch(
+            view.state.tr.replaceWith(0, view.state.doc.nodeSize - 2, initialDoc.content),
+        );
+
+        const {tr} = view.state;
+        expect(collapseAllNestedListItems(tr)).toBeNull();
+        expect(tr.docChanged).toBe(false);
+    });
+
+    it('should correctly collapse adjacent wrapped siblings', () => {
+        const view = new EditorView(null, {
+            state: EditorState.create({schema, plugins: [collapseListsPlugin()]}),
+        });
+
+        const initialDoc = doc(
+            ul(
+                li(ul(li(p('First wrapped')))),
+                li(ul(li(p('Second wrapped')))),
+                li(ul(li(p('Third wrapped')))),
+            ),
+        );
+
+        view.dispatch(
+            view.state.tr.replaceWith(0, view.state.doc.nodeSize - 2, initialDoc.content),
+        );
+
+        expect(view.state.doc).toMatchNode(
+            doc(ul(li(p('First wrapped')), li(p('Second wrapped')), li(p('Third wrapped')))),
+        );
+    });
+
+    it('should correctly collapse adjacent wrapped items with remaining content', () => {
+        const view = new EditorView(null, {
+            state: EditorState.create({schema, plugins: [collapseListsPlugin()]}),
+        });
+
+        const initialDoc = doc(
+            ul(li(ul(li(p('A'))), p('A-extra')), li(ul(li(p('B'))), p('B-extra'))),
+        );
+
+        view.dispatch(
+            view.state.tr.replaceWith(0, view.state.doc.nodeSize - 2, initialDoc.content),
+        );
+
+        expect(view.state.doc).toMatchNode(
+            doc(ul(li(p('A')), li(p('A-extra')), li(p('B')), li(p('B-extra')))),
+        );
+    });
 });
+
+describe('CollapseListsPlugin + MergeListsPlugin integration', () => {
+    it('should collapse wrapped nesting and merge resulting adjacent lists', () => {
+        const markdown = [
+            '- 1. First item',
+            '- 2. Second item',
+            '',
+            'Some text between',
+            '',
+            '- 3. Third item',
+        ].join('\n');
+
+        const parsedDoc = parser.parse(markdown);
+
+        // register merge BEFORE collapse — same order as production (index.ts)
+        const view = new EditorView(null, {
+            state: EditorState.create({
+                schema,
+                plugins: [mergeListsPlugin(), collapseListsPlugin()],
+            }),
+        });
+
+        view.dispatch(
+            view.state.tr
+                .setSelection(new AllSelection(view.state.doc))
+                .replaceSelection(new Slice(parsedDoc.content, 0, 0)),
+        );
+
+        const resultDoc = view.state.doc;
+
+        expect(hasRedundantNesting(resultDoc)).toBe(false);
+
+        // count top-level bullet_list nodes — the first two items should
+        // be in one list (merged), the third after the paragraph in another
+        let bulletListCount = 0;
+        resultDoc.forEach((child) => {
+            if (child.type.name === ListNode.BulletList) bulletListCount++;
+        });
+        expect(bulletListCount).toBe(2);
+    });
+
+    it('should merge adjacent same-type lists produced by collapse', () => {
+        // two separate bullet lists that each contain redundant nesting
+        // after collapse, the lists are adjacent and should be merged
+        const view = new EditorView(null, {
+            state: EditorState.create({
+                schema,
+                plugins: [mergeListsPlugin(), collapseListsPlugin()],
+            }),
+        });
+
+        // two separate top-level bullet lists, each with redundant nesting
+        const initialDoc = doc(ul(li(ul(li(p('A'))))), ul(li(ul(li(p('B'))))));
+
+        view.dispatch(
+            view.state.tr.replaceWith(0, view.state.doc.nodeSize - 2, initialDoc.content),
+        );
+
+        const resultDoc = view.state.doc;
+        expect(hasRedundantNesting(resultDoc)).toBe(false);
+
+        // after collapse both items are flat, and merge should
+        // combine the two adjacent bullet_lists into one
+        let bulletListCount = 0;
+        resultDoc.forEach((child) => {
+            if (child.type.name === ListNode.BulletList) bulletListCount++;
+        });
+        expect(bulletListCount).toBe(1);
+
+        expect(resultDoc).toMatchNode(doc(ul(li(p('A')), li(p('B')))));
+    });
+});
+
+function hasRedundantNesting(node: Node): boolean {
+    let found = false;
+    node.descendants((child) => {
+        if (found) return false;
+        if (child.type.name === ListNode.ListItem && child.firstChild) {
+            const fc = child.firstChild;
+            if (fc.type.name === ListNode.BulletList || fc.type.name === ListNode.OrderedList) {
+                found = true;
+                return false;
+            }
+        }
+        return true;
+    });
+    return found;
+}